1. Field of the Invention
The present invention relates generally to the field of nanomaterials. More particularly, it concerns methods of depositing metals using self-assembled monolayers at weakened points within the self-assembled monolayers.
2. Description of Related Art
As device dimensions for integrated circuits continuously scale downwards, significant focus has been devoted to developing alternate processes for the nanofabrication of functional structures. One of the processes being explored is called area-selective atomic layer deposition (A-SALD) (Chopra, et al., 2016; Kim, 2003; Ritala and, Leskelä, 2002; Leskelä and Ritala, 2002; Ritala and Reskelä, 2002). In contrast to conventional lithography techniques, A-SALD does not require any subsequent etch steps making it a promising alternative for patterning. In a typical A-SALD process, a surface is patterned with functional groups that have different reactivities to both of the ALD precursors. The ALD precursors react selectively with one of these regions of different functional groups and in a self-limiting fashion, deposit only in the preferred region until the desired thickness of the pattern has been achieved (Chopra, et al., 2016; Lee and Bent, 2011; Mackus et al., 2014; Mackus et al., 2012). In general, these functional groups are deposited using techniques such as microcontact printing, photolithography, and nanolithography have been used to create these surfaces with different reactivities. These methods, however, are very challenging to apply over surfaces that already have curvature and rely on lithographic and etching techniques to get this initial surface.
To deposit self-assembled monolayers (SAMs) such that they block particular regions of a surface, previous research has relied on conventional patterning techniques such as microcontact printing, photolithography, and nanolithography (Saner et al., 2012; Prasittichai et al., 2013; Chen et al., 2005). In addition to being expensive, these methods face the conventional resolution limits of lithography and are challenging to apply over features due to issues with alignment (Thoms et al., 2014). They are thus limited in their application. Thus new methods of using SAMs which allows for the directed deposition of metals onto curved surfaces are needed.